The utilising of innovative combinatorial chemistry and high-throughput screening tools in drug discovery has led to more active pharmaceutical ingredients with poorly soluble properties reaching clinical stages of drug development processes. It is estimated that two out of five pharmaceutical compounds in the US market are considered poorly soluble (Fahr & Liu, 2007). Poorly soluble drugs are very challenging during pharmaceutical development as solubility, and further dissolution tends to be the rate-limiting step for these compounds entering the systemic circulations and giving the desired therapeutic response (Conway and Asare-Addo, 2016). To overcome this issue, several techniques are used. These techniques can be classified into three main categories (Savjani, Gajjar, & Savjani, 2012) : I: physical modification such as particle size reduction or crystal habit (polymorphs and amorphous forms) II: Chemical modification such as salt formation. III: Miscellaneous techniques such as supercritical fluids,

In this paper we describe an easy, reliable, versatile and inexpensive laboratory experiment to teach the metabolic transformation of hydrolysis to Pharmacy students. The experiment does not require the sacrifice of any experimental animal, or any work with organs or tissues, and so can be implemented in a typical university chemistry laboratory. We used acetylsalicylic acid (ASA), hexyl salicylate (HS) and two enzymes, a lipase and an esterase. Since both ASS and HS liberate salicylic acid (SA) upon hydrolysis, students can evaluate the different enzymatic transformations by monitoring the amount of SA liberated. The learning outcomes are an enhanced student understanding of: (1) the process of hydrolysis; (2) the application of enzymatic transformations of molecules from food to xenobiotics; (3) the differences between the general specificity of substrate of both enzymes; (4) the concepts of the lipophilic pocket; (5) the catalytic triad and its regioselectivity in relation to the ester bond. A questionnaire was administered to participating students at three points in time: at the beginning of the module, after enzymatic hydrolysis was taught in class, and after the laboratory experiment. From an analysis of the questionnaire data we conclude that this practical helped Pharmacy students to understand these concepts.